Abstract SnSe-based thermoelectric materials have captured much attention since single-crystal SnSe exhibited record high ZT. However, the practical application is limited due to the poor mechanical properties and harsh production conditions of single crystals. Herein, we achieve high thermoelectric performances and enhanced mechanical properties in the Na-doped polycrystalline SnSe through implanting carbon nanotubes (CNTs). The CNTs are truncated and uniformly dispersed within the Na-doped SnSe matrix via a combination of cryogenic grinding and spark plasma sintering technique. It is found that Na-doped polycrystalline SnSe/CNTs composites maintain high carrier concentrations of approximately 4 × 1019 cm−3 at room temperature, resulting in great power factors. The dispersion of CNTs reduces the thermal conductivity without significant deterioration on the electrical conductivity. A maximum ZT of ∼0.96 at 773 K is achieved via adding merely 0.25 vol% CNTs. More fundamentally, the Na-doped polycrystalline SnSe samples incorporated with CNTs show superior mechanical properties, which are favorable for device fabrication and practical applications.

中文翻译：

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通过碳纳米管分散增强钠掺杂多晶 SnSe 热电材料的热电和机械性能

摘要 由于单晶 SnSe 表现出创纪录的高 ZT，因此基于 SnSe 的热电材料备受关注。但由于单晶力学性能差、生产条件苛刻，实际应用受到限制。在此，我们通过注入碳纳米管 (CNT) 在 Na 掺杂的多晶 SnSe 中实现了高热电性能和增强的机械性能。通过低温研磨和放电等离子体烧结技术的组合，碳纳米管被截断并均匀分散在掺杂钠的 SnSe 基质中。研究发现，Na 掺杂的多晶 SnSe/CNTs 复合材料在室温下保持大约 4 × 1019 cm-3 的高载流子浓度，从而产生很大的功率因数。碳纳米管的分散降低了热导率，而不会显着降低电导率。通过仅添加 0.25 vol% 的 CNTs，在 773 K 下的最大 ZT 为 ~0.96。更重要的是，与碳纳米管结合的 Na 掺杂多晶 SnSe 样品显示出优异的机械性能，这有利于器件制造和实际应用。